Speedup C++ code

Question

Hi,
which of this two codes is quicker?

#define DO_NOTHING { }
void DO_NOTHING() { }

hope I will get some answers,
S.A.

Answer 1

Quicker in what way?
Do you know what each of those line do? despite of which, { } means an empty block (no instruction to execute). How can you measure the quickness when there is no workload being put on as a test?

Answer 2

https://youtu.be/YG4jexlSAjc

Answer 3

#define DO_NOTHING { } is Faster because compiler will allocate it before execution of main().